Flexible strip threading guide

ABSTRACT

A threading guide for imparting a desired twist to a flexible strip. The threading guide includes a slot for receiving the strip in edgewise orientation only and a guide surface communicating with the slot for deflecting the first edge of the strip to enter the slot through a desired twist angle so that the mere insertion of the flexible strip into the slot will impart the desired twist to the flexible strip only in a desired direction.

United States Patent 11 1 Bundschuh 1 FLEXIBLE STRIP THREADING GUIDE[.75] Inventor: John J. Bundschuh, Penfield, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

[22] Filed: Feb. 26, 1973 [21] Appl. No.: 336,141

52 u.s.c1...; ..226/91,226/197,242/76, 352/157 51 1111. c1 ..B6Sh 23/32[58] Field of Search 226/196, 197, 91; 242/76, 242/157; 352/157 [56]References Cited UNITED STATES PATENTS 2,250,138 7/1941 Sheperdson226/196 X Apr. 9, 1974 2,890,619 6/1959 Waller 226/196 ux 3,094,2936/1963 Schultz 226/196 x 3,548,783 12/1970 Knapp 226/197 x 3,707,25412/1972 Scott 226/197 Primary ExaminerRichard A. Schacher 5 7] ABSTRACTA threading guide for imparting a desired twist to a flexible strip. Thethreading guide includes aslot for receiving the strip in edgewiseorientation only and a guide surface communicating with the slot fordeflecting the first edge of the strip to enter the slot through adesired twist angle so that the mere insertion of the flexible stripinto the slot will impart the desired twist to the flexible strip onlyin a desired direction.

2 Claims, 4 Drawing Figures FLEXIBLE STRIP TI-IREADING GUIDE BACKGROUNDOF THE INVENTION prevent surface damage. While this could most readilybe prevented by utilizing controllable manual threading techniques, atypical operator may not have the necessary mechanical dexterity toaccomplish such techniques. An example of such a problem area is thatconcerned' with motion picture projection filmthreading which must beaccomplished by even the most uncoordinated. In order to simplifythreading of motion picture film, automated threading devices have beendeveloped which closely approximate desired manual threading techniques.

Threading problems are further complicated if it is necessary to imparta twist to the strip being threaded. The twist usually must take placein one direction only so that a particular orientation of the strip maybe maintained. The twist problem in flexible strip transportation wasconsidered in the German Pat. No. 2,024,646 in the name of Agfa-GevaertA. G., published June 22, 1972, and the British Pat. No. 1,206,043 inthe name of the Rank Organization Limited, published Sept. 23, 1970. Ineach of the identified publications a guide channel is used to impart adesired twist to a flexible filmstrip. The twist must be accomplished ina specific direction to keep the film perforations and emulsion surfacein a particular orientation relative to theirrespective film gate. Theseguide channels provided inthe noted publications, while accomplishingdesired twisting, have considerable surface contact with respectivefilmstrips. The amount of contact with the surface of the filmstrippresents problems with regard to drag on the strip and possiblescratching of the film surfaces. These problems are accentuated due tothe fact that the filmstrip is fed endwise into the cited channels whichresults in contact with the film while the film is moving longitudinallyin the channels.

SUMMARY OF THE INVENTION In view of the above, it is a principle objectof this invention to provide a threading guide for imparting a desiredtwist in a particular direction to a flexible strip,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of theflexible strip threading guide according to this invention, thethreading guide being shown as associated with a motion pictureprojector having'a horizontally oriented film reel;

FIG. 2 is a plan view of the flexible strip threading guide of FIG. 1;

FIG. 3 is a side elevational view of the flexible strip threading guideof FIG. 1 showing the first opening thereof; and

FIG. 4 is a front elevational view of the flexible strip threading guideof FIG. 1 showing the second opening thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,FIG. 1 shows a flexible strip threading guide 10 mounted, for example,on a horizontal format motion picture projector 12, the projector 12being shown and described only to the extent necessary for a completeunderstanding of this inventionJThe projector 12 has mounted thereon areel 14 having a flexible strip of film 16 of well known type used inamateur motion picture apparatus wound thereon, the film 16 having aseries of perforations 18 along one edge thereof. The reel 14 is mountedfor rotation on aspindle 20. The threading guide 10 is located on theprojector 12 adjacent the reel 14 so as to permit the film 16 to beproperly threaded to pass over a guide roller 24 to be directed in aproper orientation into the film gate 22. After proper threading,thefilm 16 may be withdrawn from the reel 14 and directed through the filmgate 22 by a drive mechanism (not shown) not forming part of thisinvention.

The threading guide 10 is formed by a hollow housing having a base 26, atop member 28 and upstanding side walls 30, 32, 34 and 36interconnecting the base 26 and the top 28. As shown in FIG. 3 the sidewall 34 has a first opening 38 located therein which provides forpassage of the filmstrip 16 without interfering with the movement of thestrip therethrough. Immediately adjacent the opening 38 within thehousing of the threading guide 10 there is located a guide roller 40over which the filmstrip 16 is entrained so as .to be redirected towardsa second opening 42 located in the side wall 32 (see FIG. 4). The roller40 may be a snubber roller to compensate for changes in tension in thefilmstrip 16, and further may serve as a trip for an automatic rewindsystem for the projector 12.

The second opening 42 has major dimensional margins 44 and 46 and minordimensional margins 48 and 50 and generally conforms to thecross-sectional area of the filmstrip 16 being guided. The dimensions ofthe opening 42, however, are relatively largely increased so as not tointerfere with the movement of the filmstrip through the opening. Themajor dimensional margins 52 and 54 of the second opening are orientedwith respect to the roller 40 at an angle equal to the desired twist tobe imparted to the filmstrip l6 and at a vertical height such thatfilmstrip 16 passing over rollers 40 and 24 will not normally touch theside margins. In the instant embodiment, the desired twist is andtherefore the major dimensional margins are rotated relatively throughan angle of 90.

A slot 52 is formed in the top member 28 and intersects the firstopening 38 to provide communication therewith through the top 28. Theslot 52 continues to the side wall 32 wherein a slot 54 is formed whichconnects with the minor dimensional margin 48 of the secnd opening 42.The slot '52 is configured so as to per- -mit.passage of the filmstrip16 only when it is in an e'dgewise orientation. The slot 54 isconfigured so as to form a deflection surface for the edge of the filmentering the slot 52 to twist the filmstrip through a desired angle.

With the slots 52 and 54 thus formed, as shown in FIG. 4, when a stripof film 16 is inserted in the slot 52 at one end it may be entrainedover the guide roller 40 so as to extend through the first opening 38into the hollow interior of the threading guide 10. Because of thecurvature of the slot 54, as the edge of the filmstrip 16 (not havingthe perforations 18) enters the slot 54, the film will be twisted untilit reaches the desired degree of twist as it enters the opening 42. Dueto the particular described configuration of the slots 52 and 54, thetwist of the film 16 being threaded can only be accomplished in onedesired direction and is no way dependent upon the mechanical skill ofthe threader. In

this manner the perforations 18 will necessarily be maintained on thedesired edge of the film 16 for .proper feeding into the film gate 22.When the film 16 is properly threaded with the aid of the guide so thatthe film extends over rollers 40 and 24, the configuration of the guide10 and its opening 42 is such that the film will not contact the openingduring normal operation.

From the foregoing, it is readily apparent that there is herein provideda novel threading guide of simple construction for insuring the properthreading of a flexible strip. The threading'guide has a slot forreceiving the strip in edgewise orientation only and a deflectingsurface communicating with the slot for deflecting the first edge of thestrip to enter the slot through a desired twist angle so that the mereinsertion of the flexible strip into the threading guide through theslot will impart the desired twist to the strip only in a desireddirection. Because of the configuration and location of elements of theguide, the flexible strip will normally have no contact with the guideso as to substantially eliminate the possibility of damage to the strip.

The invention has been described in detail with reference to a preferredembodiment thereof, but it will be understood that variations andmodifications can be effected within the spirit and scope of theinvention.

I claim:

1. A threading guide for facilitating threading of a flexible strip froma first roller guide to a second roller guide, said second roller guidebeing oriented at an angle with respect to said first roller guide, saidthreading guide including a guide body having an opening therethrough ina direct line between said first roller and said second roller, saidopening being configured so as to permit unrestricted travel of saidflexible strip therethrough, a longitudinal threading slot in said guidebody extending in a direction generally parallel to the path betweensaid first and second roller guides, said threading slot beingconfigured to receive said flexible strip only when a lateral edge ofsaid strip is in an edgewise orientation with respect thereto, and adeflecting surface between said threading slot and said opening, saiddeflecting surface being configured to deflect alateral edge ofaflexible strip through a desired twist angle whereby a flexible stripthreaded into said slot in an edgewise orientation will assume a twistgenerally conforming to the difference in orientation of said rollerguides. 2. A guide for threading a flexible strip into a travel pathhaving a desired twist angle, said guide comprising: a body; alongitudinal slot in said body, said slot extending generally in thedirection of said desired travel path to establish a threading entranceto said guide for said flexible strip when a lateral edge of said stripis in edgewise orientation with respect thereto; and a deflectingsurface communicating with said slot and said desired travel path, saiddeflecting surface being configured so as to deflect a lateral edge of aflexible strip threaded into said slot through said desired twist angle.

1. A threading guide for facilitating threading of a flexible strip froma first roller guide to a second roller guide, said second roller guidebeing oriented at an angle with respect to said first roller guide, saidthreading guide including a guide body having an opening therethrough ina direct line between said first roller and said second roller, saidopening being configured so as to permit unrestricted travel of saidflexible strip therethrough, a longitudinal threading slot in said guidebody extending in a direction generally parallel to the path betweensaid first and second roller guides, said threading slot beingconfigured to receive said flexible strip only when a lateral edge ofsaid strip is in an edgewise orientation with respect thereto, and adeflecting surface between said threading slot and said opening, saiddeflecting surface being configured to deflect a lateral edge of aflexible strip through a desired twist angle whereby a flexible stripthreaded into said slot in an edgewise orientation will assume a twistgenerally conforming to the difference in orientation of said rollerguides.
 2. A guide for threading a flexible strip into a travel pathhaving a desired twist angle, said guide comprising: a body; alongitudinal slot in said body, said slot extending generally in thedirection of said desired travel path to establish a threading entranceto said guide for said flexible strip when a lateral edge of said stripis in edgewise orientation with respect thereto; and a deflectingsurface communicating with said slot and said desired travel path, saiddeflecting surface being configured so as to deflect a lateral edge of aflexible strip threaded into said slot through said desired twist angle.2. A guide for threading a flexible strip into a travel path having adesired twist angle, said guide comprising: a body; a longitudinal slotin said body, said slot extending generally in the direction of saiddesired travel path to establish a threading entrance to said guide forsaid flexible strip when a lateral edge of said strip is in edgewiseorientation with respect thereto; and a deflecting surface communicatingwith said slot and said desired travel path, said deflecting surfacebeing configured so as to deflect a lateral edge of a flexible stripthreaded into said slot through said desired twist angle.